Good design takes people's natural behavior into account, rather than forcing unnatural solutions on them. In this example from Amsterdam, we see the importance of observing that behavior and working with it to solve a problem.

The problem is that cycling in Amsterdam has increased by 40% over the last 20 years, meaning their bike lanes are growing overtaxed. One particular bicycle crossing called Mr. Visserplein has 20,000 cyclists passing through it each weekday, and the congestion is taking a toll.

Amsterdam's city planners analyzed the issue and came up with a two-pronged approach:

Enter a caption (optional)

I found the bit about the cones the most interesting.

Before

Enter a caption (optional)

Enter a caption (optional)

After

Enter a caption (optional)

Enter a caption (optional)

When a huddle of stopped cyclists all begin to move, obviously human variety means some will move faster, others slower; thus by the time they reach the narrower aperture at the other end of the crossing, they will have automatically--absent any need to cooperate--sorted themselves out as a group and can wheel neatly through the slot.

This reminds me of the thing that irritates me most in subways: People on the platform attempting to enter the train while folks are still exiting. The people muscling their way in want a seat and are motivated by self-interest. Thus my proposed solution is to have subway doors that swing out onto the platform and have edges lined with poison-tipped spikes.